1999 139 yamaha shutting down while running

have a yamaha 1999 130 after about 2 miles of running alarm goes off and engine shuts down. cut engine off turn back on will run again. replaced water pump; no change; any suggestions

[jb123]

shuts down..... or goes into rpm reduction ???

next time you go out, unplug 10 pin main and run it, it sounds like you have some front end electric trouble.

goes into rpm reduction

do not know if it gets hot. no temp gauge. alarm sounds but as soon as I turn engine off and back on within 10 seconds no alarm and then I am back up running

A lot of those motors get a build up of deposits on the walls of the cooling passages in the head reducing cooling efficiency and causing overheating at high speed. Another thing that can cause overheating is when the rubber oil seal cover under the waterpump plate starts to separate.

[jb123]

when is the last time you replaced waterpump, thermostats and pressure relief valve ?

have you checked the oil levels when the motor goes into reduction ?

replaced waterpump before last trip out \; have not replaced thermos or prv

oil levels are fine

ok guys i've changed waterpump----themostats----prv----fuel filter--------oil filter----tightened electrical connections-----ran motor-----same thing happen-----looks like if I stay below 3500-3800 rpms it runs fine -------over4000 rpms----buzzer and rpm reduction----when the motor did this I cut motor off pulled cover off----put my hands on head next to plugs did not feel very hot----oil level fine----telltail water cool---exhaust water warm--- anybody got any ideals------thanks

[jb123]

when it happens again pull the thermosensor wires apart and see if the buzzer stops, ensuring an overheat alarm.

when you did the pump change, did you replace the housing or just the impeller kit?

COULD be clogged jackets but but check the obvious first.

do you have any transducers etc blocking waterflow to intake?

is it a new issue or could the motor not be low enough in the water for sufficient flow ?